The present invention relates to a desiccant composition and a method of desiccating articles with the desiccant composition.
Throughout this specification and appended claims, % stands for percent by weight and the term `desiccation`, inclusive of its derivative terms, means removal of surface water from any article and is synonymous with drying and dehydration.
Wafers for the fabrication of semiconductor devices such as IC and LSI, plated articles, optical lenses, photolithographic masks, liquid display device components, electronic parts and various other parts made of metal, plastic, glass or/and ceramic materials (all referred to collectively as an article) are rinsed and, then, dehydrated in various intermediate stages of fabrication or at the final stage in the production process. Typically an article is rinsed with an aqueous detergent solution and demineralized water and, then, dehydrated. The residual water on the surface of an article can be a source of stain or rust and, as such, is an important parameter determinant of the field performance of the article.
For the effective dehydration of an article, it is common practice to use an alcohol, e.g. isopropyl alcohol or ethanol, a chlorofluorocarbon (CFC), e.g. trichlorotrifluoromethane, or a composition comprising such a chlorofluorocarbon (CFC), an alcohol and a surfactant.
However, isopropyl alcohol and ethanol are not satisfactory from workability points of view because they are highly inflammable to cause hazards. CFCs, mentioned above, destroy the ozone layer of the stratosphere so that, as frequently pointed out, they may exert serious adverse effects on the ecology of the earth, involving humans as well. Therefore, as far as the CFCs with a high risk of destroying the ozonosphere are concerned, both use and production have been restricted by international agreements.